China is prepared to use nuclear weapons against the US if it is attacked by Washington during a confrontation over Taiwan, a Chinese general said on Thursday.

"If the Americans draw their missiles and position-guided ammunition on to the target zone on China's territory, I think we will have to respond with nuclear weapons," said General Zhu Chenghu.

Gen Zhu was speaking at a function for foreign journalists organised, in part, by the Chinese government. He added that China's definition of its territory included warships and aircraft.

"If the Americans are determined to interfere [then] we will be determined to respond," said Gen Zhu, who is also a professor at China's National Defence University.

"We . . . will prepare ourselves for the destruction of all of the cities east of Xian. Of course the Americans will have to be prepared that hundreds . . . of cities will be destroyed by the Chinese."

Gen Zhu is a self-acknowledged "hawk" who has warned that China could strike the US with long-range missiles. But his threat to use nuclear weapons in a conflict over Taiwan is the most specific by a senior Chinese official in nearly a decade.

However, some US-based China experts cautioned that Gen Zhu probably did not represent the mainstream People's Liberation Army view.

"He is running way beyond his brief on what China might do in relation to the US if push comes to shove," said one expert with knowledge of Gen Zhu. "Nobody who is cleared for information on Chinese war scenarios is going to talk like this," he added.

Gen Zhu's comments come as the Pentagon prepares to brief Congress next Monday on its annual report on the Chinese military, which is expected to take a harder line than previous years. They are also likely to fuel the mounting anti-China sentiment on Capitol Hill.

In recent months, a string of US officials, including Donald Rumsfeld, defence secretary, have raised concerns about China's military rise. The Pentagon on Thursday declined to comment on "hypothetical scenarios".

Rick Fisher, a former senior US congressional official and an authority on the Chinese military, said the specific nature of the threat "is a new addition to China's public discourse". China's official doctrine has called for no first use of nuclear weapons since its first atomic test in 1964. But Gen Zhu is not the first Chinese official to refer to the possibility of using such weapons first in a conflict over Taiwan.

Chas Freeman, a former US assistant secretary of defence, said in 1996 that a PLA official had told him China could respond in kind to a nuclear strike by the US in the event of a conflict with Taiwan. The official is believed to have been Xiong Guangkai, now the PLA's deputy chief of general staff.

Gen Zhu said his views did not represent official Chinese policy and he did not anticipate war with the US.